The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Winches support a wide range of applications and assume a variety of sizes and types in order to pull or lift heavy loads. Winches can be powered by electric, hydraulic, pneumatic or internal combustion drives. For example, in electrically powered applications the winch receives a voltage supply from a vehicle battery and/or auxiliary power source to power a winch motor.
Winches are typically rated to a value, such as 10,000 lb, indicating a maximum applied force that internal load-bearing components may withstand. A load-sensing device may monitor the load level and protect for errant values attributable to external factors, such as noise, ripple voltage, and/or transient voltage in the vehicle supply voltage caused by an alternator, an ignition system, or other accessories. When uncorrected, these external factors may cause premature shutoff of the winch. Such a device, described in commonly assigned U.S. Pat. No. 6,046,893 (programmable electronic current limiter), U.S. Pat No. 5,648,887 (multi-state electronic current limiter), U.S. Pat No. 5,214,359 (electronic current limiter), and U.S. Pat No. 4,873,474 (load limiter), is incorporated herein by reference.
Frequent use of the winch may result in an excessive demand for current from the electrical supply. The current used by the winch may exceed the current supplied to the battery from the alternator. Continuous operation of the winch under this condition depletes the battery current, causing decay in battery voltage. Low battery voltage may cause performance issues with the winch and/or other accessories in the vehicle electrical system. For example, low battery voltage reduces speed of the winch motor, necessitating operation of the motor for a longer period in order to pull a given load. Additionally, the battery may not be able to provide sufficient power to operate needed accessories, or may not be able to restart the vehicle engine. A low voltage interrupt module as described in commonly assigned U.S. Pat. No. 7,262,947 may successfully obviate this problem.